Heat-electrical power conversion through the medium of a charged aerosol



A. M. MARKS HEAT-ELECTRICAL POWER CONVERSION THROUGH May 12, 1953 THE MEDIUM OF A CHARGED AEROSOL 6 Sheets--SheeI l Filed Dec. 14, 1949 www IN VEN TOR. /lL v/N M. MAR/ 5 ay l2, 1953 A. M. MARKS HEAT-ELECTRICAL POWER CONVERSION THROUGH THE MEDIUM OF' A CHARGED AEROSOL 6 Sheets-Sheet 2 Filed Dec. 14, 1949 FIG.3

Jlym INVENTOR. /ILv//v M. Mak/f5 May 12, i953 A M MARKS 2,633,555

HEAT-ELECTRICAL POWER CON S N THROUGH THE MEDIUM OF A CHAR A SOL Filed D96. 14, 1949 6 Sheets-Sheet :5

INVENTOR.

/lLv//v M. MAR/ 5 HTTURNEY May E2, E953 A. M. MARKS 27638955 HEAT-ELECTRICAL POWER CONVERSION THROUGH THE MEDIUM OF A CHARGED AEROSOL Filed Dec. 14. 1949 6 Sheets-Sheet 4 L 76 ano IN VEN TOR. /lLv/N M. MA R K6 I ,71 rok/EY May 12, 1953 A. M. MARKS 2,638,555

HEAT-ELECTRICAL POwER CONVERSION THROUGH THE MEDIUM OE A CHARGED AEROSOL Filed Deo. 14, 1949 6 Sheets-Sheel'I 5 28a HCL 29,

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May 12, 1953 A. M. MARKS HEAT-ELECTRICAL POWER CONVERSION THROUGH THE MEDIUM OF A CHARGED AEROSOL 6 Sheets-Sheet 6 Filed Dec. 14, 1949 INVENTOIL /iL v/N M MAR/f5 Patented May 12, 1953 NITED STATES PATENT OFFICE HEAT-ELECTRICAL POWER CONVERSION THROUGH THE MEDIUM OF A CHARGED AEROSOL Alvin M. Marks, Beechhurst, N. Y.

Application December 14, 1949, Serial No. 132,963

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to the production of electrical power from heat without the intervention of moving mechanical parts, except in the auxiliaries. The type of heat-to-electrical power conversion device herein employed is generally known by the term ion-convection generator. Prior art devices of this general type have produced extremely high voltages and very low current densities, and were thus not suitable for purposes of general utility, such as for ordinary power requirements for the running of electrical motors or lighting circuits. The prior art devices have been rather limited to employment for the operation of X-ray machines and the like Where high voltages and low currents were serviceable. The present invention relates more particularly to a low-voltage-high-current device of the ion-convection type.

Advantages over conventional devices, such as turbo-generators, which are complex rotating machines, include comparative simplicity, higher efciency, and freedom from vibration. The consequent economic benets are lower capital investment, lower maintenance, and lower operating costs.

It is an object of this invention to employ heat sources such as oil, coal, or atomic reactors to supply the source of heat to a working substance such as a gas or a vapor and to cause ions or charged particles to be formed within this working substance, through the processes of ionization, and to utilize these ions or charged particles under such conditions of operation as to produce electrical power at a comparatively low voltage and high current.

It is another object of this invention to establish the geometrical and physical conditions necessary for the construction of a low voltage and high current generator.

It is a further object of this invention to establish critical values for the efficient operation of devices of this nature, establishing such values particularly in connection with the proportion of kinetic power converted to electric power, and generally to relate the electrical quantities of current density, voltage and power density to the geometry of conversion space, more particularly to its length and area, and to the physical quantities such as mass-flow, velocity and particle size.

It is an object of this invention to provide aerosol particles of the size required for the proper operation of the working substances employed. The particle sizes referred to are the mean diameters of the particles of aerosol mixture employed in connection with or as a part of the working substance, gas or vapor. The aerosol particles are employed as a carrier for the electric charges.

It is another object of this invention to utilize simultaneously both the positive and negative charges created in the ionization process.

Itis another object of this invention to provide novel ionization means.

It is still a further object of this invention to employ means for increasing the value of the minimum sparking potential of the gas employed as a carrier of the aerosol particles, in order to enable the eicient conversion of kinetic power to electrical power at lower voltages and higher current densities.

It is a still further object of this invention to provide a novel electro-thermodynamic cycle in which combustion and ionization stages are combined.

This invention permits the direct conversion of heat to electric energy at extremely high initial temperatures, corresponding to the maximum attainable temperature, limited only by the static [strength of materials at these temperatures. Prior-art devices, such as turbines, were limited to a maximum of about 700 K. operating temperature due to the necessity of employing materials in the rotating parts capable of withstanding high centrifugal and other forces. For this reason a high Carnot Efficiency can be obtained with the present invention, utilizing one or more metal or other gaseous high temperature working materials, in binary or trinary cycles. Thus, for example, in the present invention:

Carnot Eiciency= T1 T2=2390 3m 100=87% 'This may be compared to a turbogenerator running at '700 K.:

Carnot Efficiency:

cross-section of an ion convection generator showing a preferred embodiment of the invention;

Fig. 2 shows a fragmentary plan view of the nozzle plate;

Fig. 3 shows a fragmentary perspective cut.- away view of the assembly 'of the device of Fig. 1;

Fig. 4 is a fragmentary, partly diagrammatic cross-section, along a nozzle axis, of .anothertylle of ion convection generator .employing a point ionizer means;

Fig. 5 is a cross-section of the device of Fig. f1, along a plane normal to the nozzle axis;

Fig. 6 is a fragmentary perspective view of still another form of this invention employing a p0- rous grid ionizer structure;

Fig. 7 is a cross-section of Astillanother form of this invention, in which the steps of combus-l tion and ionization are combined;

Figs is aeiagram of the nozzle. ood

the various physicalmathematical .quantities in relation1;heret'o;l i

` 9 is a block diagram of one Vofltloie thermaldynamic cycles employed in 'connection with this invention, and also indicated method of producing. anaerosol;

"Fig, 10 is a graph of accepted experimental values4 of breakdown voltagef-plotted against pressure times distance between gap electrodes; Fig. 11 is a graph of a relationship between nozzle .dimensions and kinetic-to-electric power conversion; and

Fig. 12 is a log-log graph, on which is plotted relationships discoveredV between power density voltage, .current,.density, nozzle. length, gas ve.-

looity, conversion ratio, mobility, etc.

Before proceeding to the description of the drawings, certain physical conditions of opera..-

tion are predicated, from which myumathematical physics analysisfollows.

` The 'purpose of. 'the `mathernatical physics a nly sis presented vherein is .to deriveequations forv voltage, current' and electrical power, and 4to relate these quantities tothe mechanicalnuantities ofkinetic power, velocityof thewlorlingsubn.

stances or gas, and to thefgeometric. construe?. tion of the".conyerter., space, particularly the length and area thereof. In addition, .account is taken 0f the Proponi@ vof. mehllfl .P9-iwf" converted tov electrical power, the. sizeof the,

aerosol particles employed, and' their mobility in the electric field, yas related to, viscousor fric.

tional power" loss- Io addition, oo'nsiolgroiioo is given to thepossibility of electrical f lashbval;` occurring inthe conversion space, due to carpes.,-`

sive electrical intensities being built up, and a. limitation is established based .0n the known:

ooooiion for minimum .sparking potentiel;

Finally, the 'equations are plotted upon the graph shown inV Fig. 12; andlsarnple calculations arey made for Acer-tain `lowfvoltage-high-current generators, for the purpose of illustrating the construction,*particularly the order of themagf nitudes of the geometric and physical quantities involved in practicing this invention.

As stated, the derived equations have been simplified by certain assumptions. VIt will be understood, hoWoi/oil iifioioiiio ooiioliiioro.

opration may bo piosiiooiod, an@ ofoh oojiiiooo derived oo o basis .for other embodiments Wohin iloo Scopo .of this invention; Aooordegly, i yysi..

119.12150l loolimoo by the .thooiotioo ,weiterhelfein "presented, ,but only by folioy full, .scopo the Soooifiooiion ond. apoodoooloimof.

Symbols and deymmmw In Fig. 8, the subscripts l and 2 refer to initial and terminal conditions in a nozzle of a device according to this invention: that is, at the high- .and low-velocity ends o fqtheconversion space thevelocities are U1 and Ua and the cross-sectional area is A1 and A2, respectively. Symbols Without subscripts refer to conditions at the generalized `.eros,s1-sectional area A, unless otherwise spei (It is understood, however, that inthe cese of.. larger ohorsod particles. more than. .one .elect-ron. Charge .may be present.)

f=a function defined by Equation 66.

f1=a function defined vin Edlu'ationy 68 fp=ratio p/p; or, in the nslzzle4 plate, the ratio of average power density 'to the power density at the nozzle throat.-

I=tota1 ion current across the entiresection A.

Hu =inp ut ofthe heat content of hthe gas, prior to expansion, into the nozzle.

H1=output ofthe heat content ofthe gas Aafter expansion' ono iiioon. ofoi'roiioo io Sooiion .4.1i Ho and H1 can be measured kilogramcalcries per kilogram per secondi.4

i: current density j current per unit area.

J=conversion factorbetween heat units andu-nits of i mechanical energy; lc=mobility of a charged particle, at section A, (Fig. 8) where the Mobility of the charged- Poiriiolo is that yolooiiy imparted io @ho ooriiole ihroiisli. tho eosin; whioh it is .oontainedxby aiioloof'uniiolooiitio intensity 1.o this. .definir tion, the. velocity. of lthe particle is considered.

Zemoan. free Path of. eos; l thosomooi S.Ty .P- loedioioiioo between nozzles.

L=lneth of. thenozz'le between .Sections al and.

Pi=..i.oi.o.1 olooirio power oooverted. f romiineip.

power,A (doe .io slowiii the. noiionoi themas). .1.1i too. oni-iro. ooiiyorsioii .Spooo from! Xiao to.

.ocioss-thoo1iiti1to area o f,.1;r 1 e 'ac zzie.

liaise:-

p=P/A=electric power converted from kinetic power per unit of cross-sectional area in the nozzle; that is, the generated electric power density.

p=average electric power density over the plate containing the nozzle array.

Pf=tota1 frictional power loss produced by the relative motion of the ions or charged particles relative to the gas, across the entire area of the nozzle.

pf=pf/A=frictional power loss per unit of crosssectional area.

Pwr-:kinetic power, or the flow of mechanical energy due to the velocity of the mass of gas, including the mass of ions or charged particles, passing through the section A.

PmzPm/A; the average kinetic power per unit area.

r=radus of nozzle.

T=Temperature of the gas.

U=Velocity of the neutral gas or vapor.

U=Velocity of the charged particles. In general U U owing to the repulsion exerted by the electric countereld gradient.

V=Electric potential at a distance x, at section A. By denition; V=0, at x=0.

Vs=potential difference causing sparking in gases.

X :electric intensity, or the counterfield gradient against which the gas must do work in increasing the electric potential of the charged particles, at section A.

=distance along the nozzle between sections A1 and A.

aEThe ratio of the relative velocity of the ions or charged particles with respect to the gas, to the total velocity of the gas, at the section A, or (U-U) /U.

4 =apex angle of the cone of the nozzle.

y=The fraction of the total kinetic power in the gas stream, which is converted to electric power in the nozzle.

yc=The critical maximum proportion of kinetic power that can be converted into electrical power, in the nozzle; that is:

=The average mass density of the gas stream,

including suspended particles, if any.

o=The average mass density of the gas stream, excluding the suspended particles, if any; 6u same, at S. T. P.

=Critical gas density necessary to avoid ilashback.

p=Electric charge density at section A.

eo=Dielectric constant of free spacc--8.85 l012 in the m. k. s. system.

In carrying out this derivation, it will be understood that:

I. The gas stream has an initial velocity U1, imparted to it, for example, by an expansion of the gas in a nozzle from a condition of input of high heat content Ho, to a condition of output of low heat content, H1, prior to entering section A1. The difference in this flow of the heat contents is converted into kinetic power; thus:

II. Substantially no thermodynamic change occurs along the nozzle from 32:0 to :1:=L in the conversion space; that is, pressure, tempera- 6 ture, volume and heat content remain substan-I tially constant.

To accomplish this purpose, the nozzle area, A, is increased at a rate approximately inversely proportional to the decreasing velocity U. That is, approximately:

AUEConstant (3) In this manner mass ow M, gas density, o, and temperature T of the gaseous medium can be maintained substantially constant across all sections. To correct for variations in Equation 3 due to small frictional losses which act to increase the heat content of the gas, it may be necessary to make the area somewhat larger than calculated according to (3). The drop in kinetic power, produced by the reduction in the mass velocity, U, as A is increased, is converted to electric power, as hereinafter described.

In another embodiment of this invention the area A may be increased in greater than inverse proportion to the decrease in the velocity. In this case further thermodynamic change will occur in the conversion space; that is, gas density and temperature will drop during the increase in electric potential energy of the charged particles; and the thermodynamic energy will be converted simultaneously to electric energy. However, although within the purview of this invention, this case will not be treated mathematically herein.

III. The frictional power losses are held to a small fraction of converted power. This is done by employing an ion or aerosol particle having a sufficiently low mobility to minimize slip. This result is obtained by using a charged particle of sufficiently large diameter. In this manner the relative velocity oi ion and gas stream, due to slip, is minimized; and thus the frictional power losses due to such slip velocity are kept small relative to the generated electric power.

IV. The meter-kilogram-second system of units will be used.

M athematicaZ-physical analysis Let there be a stream of gas containing ions of one sign comprising an aerosol containing charged particles, in which there is substantially no slip, or relative motion, between the ions or charged particles and the gais stream. The condition for this is for the mobility lc to be very small.

The total current L is given by:

I :neAU (4) The electrical energy developed per unit of time, or electric power conversion in the increment of length da: is given by:

7. The-charge density, p, isfgivenby:

Since'AU. is. constant, by (3.), and: since,r Lis constant, it follows that the charge'.-density,.p; isi also constant.

Next, the potentialVv distribution due to the space charge and the superimposed load voltageE will becalculated, using Boissonsl eguation, asfol: lows:

ag-:faz Integrating this" the countereldelectrieim tensit'y X gpl/gnb# Y aV s La e) Int'eglilg again. the potential distribution is. given by the fguwing f The cpnstantsof integration, 1C; and C2, are

now evaluated subject to the followingcondif From (14) it is apparent that the electric intensity is a maximum when"=.0, and that X decreases linearly to :c=L. When 2:1., and in the region immediately preceding L itiisv esseritial that' the values of X do vnot become negative.

IfX were permitted to become negativefthen' the electric energy would be converted ybackagainl into kineticenergy thereby causing the velocityl of the gasstream to increase again, causingy aY reduction in the overall conversion emciency. Hence, there isa criticall value of'X, suchf'that X=O, at :1::L. Making use of this relation, and putting X=o at =L into 14), there is now obtained anexpression for the electric intensity along a converter space, under the desired condi'- tion of operation, 4as follows:

`The electricV intensity along, the., conversion space is then determined by substituting (16) intoy (14) with the following result:

The maximum electric intensity occurs When a'ndfthe correspondingvaluev off electric-inseameeen-af f l s IL XOTAUMQ. The total electricfpcwer converted from'kinetic power isigive'nby f f 'Y 2AU1 Inl terms of' power density yand' current density, dividing (19) through by A, there fis obtained:

It willbe understood that p, and z',.are::values taken at a particular nozzle section, such as'the areaAn'; at the .nozzle throatyand Ev-'is the poten; tial diierenceV across the entire length L of the c'onversi-onspace;y l 'f' A' In Fig. 12, there is plottedl )analog-log scale, power."'density- Ain' -.watts'iper square:nreteras` Ordinates versus velocity' in meters per second; las ab'scissae'for various values of' E`/L from'Equation 232i 'Ilherefi's ."alsoplottedlionthe fsazme` scale several additional.'familiesofl curves; one Vfamily of curves being for various mines, of.A zL from Equation- 21'; another family 'of 'curves for E/L from?Equation1'.23`;."etc. 1

The' 'mass'rowf per.` unit area, is given by:

M A' fU' The kinetic power-densityk which is. converted into electrical power density, is given the following, upon making the "substitution from 24:

CRITICALoPERArmGlcoNDrrIoNsf- 1'. LIMITATIONS DUE To ELEcrizIc FLssAoK (a) firewall-,gas @gaat se The critical values of 'ycand 6c, :are those Values that determine)tliefmaximum'fraction' o-f kinetic power converted-'S tot v'electric power, without exceeding the breakdown potential? of the gas, and thereby causing flashback or a short-circuiting, electric discharge Within the conversion space.

'.It: is.` now? required: tof determine the: conditions imposed by the necessity to avoid lashbacksf within/the gas-stream.

Illmpiricaglly it: hasrkneenl determined.' that the sparking. voltagergVs is 'that potential diierence required to'justcauseria; sparkbreakdownfthrough agas of`density o,1wit h the electroderdistance L,A

given .approximatelyz'byt 'Vpbaoz 26) This relation holdsf'true only` above certain Values of L. Asan example, experimental data iiftlair or-nitrgerf'f'asafworkiiig medium are plotted-inthegrapli Fig'u're 10.5 Tl'i'dataare plotted? fwitli the -Jord`1na`.t'es the z'ninimuniI 9 sparking voltage, and with the abscissae as the product OL. The equation for` the `curve experimentally obtained is given approximately by:

Vs-3000=2.50 1065L (m. k. s.) (27) `Norme-On rechecking calculations, the value of b for an' 1s 2.25 X 10. This will effect subsequent calculation by 10% but will not alter the order of magnitude of the results; :2.50 10 applies to slightly inhibited or impure air.

In general terms the above may be expressed: Vs=CiboL (28) Where C=3000 and b=2.50 106 (27) Putting VS=E and dividing through (28) by L there is obtained the following:

E C =+bo (29) From (23) and (29) there is obtained:

1 C vax/ib] 30) Making the substitution from (25) into Equation 30 there is obtained the following:

The condition for the approximation (26) to hold is given by the following inequality:

The double inequality sign indicates that the larger quantity is greater than the smaller quantity by a factor of the order of ten or more Putting the numerical values for b` and C from Equation 27 into the inequality (32) and utilizing a value of L of the order of 1'0-2 meters, the minimum value of for which (26) is in error by less than may be computed as follows:

S. T. P.=1.293 ken/m?. Hence if a gas density, in excess of the value given in (33), is utilized, approximation (26) may be used and the term C/L in Equation 31 may be neglected.

It is further assumed that 6:50; that is, the aerosol particles do not substantially increase the gas density. --o is now changed to c to) indicate it is a critical gas density. This assumption will later be shown to be justified by a calculation which shows that the total mass of the aerosol particles must be of the order of 0.03 to 30% of the mass of the gas in which they are entrained, assuming only one electron charge per aerosol particle, under typical operating conditions.

Under these circumstances, solving (3l) for 5c: when Substituting the Value for 5:56 from (25) into 34) and solving for the critical gas density 6c,

there is finally obtained an expression relating an to the electric power density p and the velocity U1; thus For the particular experimental data for air or nitrogen the Equation 35 may be evaluated with the following results:

The Equation 35 `is plotted, for various values of 5c greater than that given by (34), on Fig. 12.

(b) Power conversion factor a NUL,

Putting in the values of b, for air or nitrogen, and eo, there is obtained From Equation 37 it will be seen that for a given kinetic power density and a, given gas velocity, the greater the value of b, that is: the greater the slope of Vs, nL graph in Fig. 10, the greater the proportion of the kinetic power density there can be converted into electrical power.

It is a feature of this invention to employ means for increasing the value of b, as for example the introduction of spark inhibitors such as Freon, carbon tetrachloride, or chlorine, into the gas stream. However, in Fig. 12, a plot of Equation 38 for various values of yc is shown, for the value of b, given above, for nitrogen or air. Also, another scale is shown for a value of b ten times the value given for air.

In order to summarize all the pertinent data Fig. 12 has been constructed with the ordinates plotted as a log of the electric power density, p, and the abscissae plotted as the log of the velocity of gas flow U1. On this log-log graph the following equations have been plotted: Equation 21 for various values of the product iL; Equation 23 for various values of the average electric intensity E`/L; Equation 35 for various values of the critical gas density 5c; and, Equation 3'7 for various values of the power conversion factor fyc. In this manner there may be quickly determined for any given value of converted power density, and power conversion factor, values of current density and potential difference built up across a nozzle of given length. In addition to this, critical gas density 5c, and mobility reduced to STP, Ko, are also shown.

(c) Effect of spark inhibitors In general, the use of spark inhibitors, such as Freon, prevents the formation of ions, in the ionization stage. Accordingly, I prefer to separate the ionization stage and the conversion stage, utilizing a readily ionizable gas in the ionization stage. After the ions are formed the ionizable gas, with the ions contained therein, are mixed with the aerosol gas containing the spark inhibitor. The aerosol particles pick up the ions and become charged, and the conversion from kinetic to electric power then proceeds in a gas With a higher dielectric breakdown strength.

The effect of increasing the dielectric breakdown strength of the gas is to increase the slope b of the curve shown in Fig. 10. Gases that can be employed for this purpose include Freon, carbon tetrachloride, chlorine, alone or mixed with air for example. I'he value of b can in this way #electrons are rapidly captured, thus inhibiting electron avalanches or sparks.

as A-'zvery important feature of this driven-tion is `theutilization vof 'aerosol containing gases or vapors that have ahigher dielectric strength, or an increased value of b, over that of air.

rv Inspection of Fig; 12 lwill :illustrateithe effectsr 1of^increasingi b. f'I-'akinggivenvalues foripower :density v -nozzle .length L, wand conversion-eni- 'ciency y; then,increasing. b,.we obtain: increased current density,.lo.wer voltage, lower gas. density,

increased gas velocity. Also, the aerosol par-f aticle size is increased somewhat. See Example 2, hereinafter.

f1-The extremely :shortiixlength :ofzgnozzle 1 is* ganother very important featureof thisinvention. The short nozzle enables a relatively low volt- `lage to be generated, and overcomes the currentdensity limiting eifects of space charge encoun- 1 tered with the long nozzles previouslyemployed .The array-.of short nozzles permits anl unlimited rtotal cross-sectional -areapf nozzle to be Aob tained. l 1` Thus, vahigh current, relatively low voltage generator can -be yconstructed according tothe principles, operatingy vunder the physical ,conditions -of theorder of magnitudev set forth in Fig. 12, and the accompanying equations. rTo explicitly determinelthe liwayfin which --E/L,iL, and -p are 'determined by Vthe .chosen values of b and fyc, the following vequations are derived. y f --FromEquations 23 and -3'7, eliminatingp, it

follows that: y

E 2 v I-lebUl (39) Y IFrom'llquations 21 and"37, eliminating rin, it

follows that:

-le 3 Y VzLzbUl (40) AFrom (39) and (40).and

' E, L* i p--'LL-Er 1 2 5 @(Qm A 11) Y Inthe'following examples, the power densities and current densities should be fdivided--by a Vfactor of about-4 to `obtain theea'ctualputputs per square meter. "This reductionffactor lisi-applied tothe olosely-packednozzles in the nozzle plate, since this is :approximately :the ratio of the total area of the nozzle plate, to the total "area-of Iall the' nozzles-taken at'- their throat, or

"th'emost Yprecise determination of calculated values.

v ExaMrLE I Constant velocity Y Let- 76:..885' t 12 'r11-ELE i [Exampleofvoltage'Cuxrent'poWer for a pure air and an Y v inhibited.aerosol.]

` Pure inhibitd" From-Edu y Symbol Units aerosol .Aerosol Y b=2.50 X 10 b=2.50 X 101 '(39) E Voinsm. 125,000 12, 500 (40) i amp/1n. 4. 43 0. 443 :p watts/m 555, 000 5, 550 kg./m.3 10 0.1 a0 nicters 1.27 X 10-s 4 10-8 1 Noria-at S. T/PY n =1.293 kgJm.

EXAMPLE'II lo Constant power density 'Let 70:0.9 111---10L Watts/in.2

L=5 103 meters TABLE 2 l 1 "Pure" inhibited From Equ.. Symbol Units aerosol aerosolb=2.50 106 vb=2.50 107 (41) U1 "meters/sec. 22.2 55. 3 r' amps/111.2. 0.397 0. 632 E volts 25 200 15, 800 '(35) '6c KgL/m 3 2. 0 0.129 zo meters 1.9 X 10-B 3 8 X 10-5 ExAMrLE. III

Constant'ctical' yasdensity '(at standard temperwture and pressure) TABLE 3 l(.214.) U1 f meters/sec... 18. 1 181 ,5 (as) E `vous 0060 @6,000

(40) z amps ./m.2 0. 5 50.

(fi `p -watts/m.2 3,300 3,300,000

Comparison of the last two columns shows the :very large current density and power output obtainable with the inhibited aerosol compared to the pure air aerosol.

. This important-result permits the compact design of high output generators.

2. THE CHARGED PARTICLE :(a). Limiting maz'mam particle mobility values for elcz'ent operation It is neXt required to determine the value of Ithe mobility lc of an ion, or charged particle, re- 'quired to reduce the slip factor a, to some predetermined value, such that, the energy lost in -thefviscous motion of the ion, or charged particle, relative to the gas will be maintained at a comparatively negligible value. By definition:

Where a represents the fraction of power lost to random gas motion caused by the viscous motion of the ion, or charged particle through the gas. This may be readily seen by multiplying the numerator and denominator of (42) by F', which is the force exerted by the gas in moving the ion or charged particle against the counterfield at the velocity U; FU being thus the kinetic power converted into electrical power in the form of time rate of increase of the potential energy of the ion or charged particles plus the fraction of the kinetic power of the gas stream which is converted to random heat motion within the gas, or, frictional power. The ion or charged particle must exert an equal and opposite force, F, which force is expended 'as a power loss of viscous motion relative to the gas stream at a velocity (U-U): consequently, the frictional power is given by: F(U-U). This may be expressed as follows:

F(U-U) Frictional Power Loss F Total Kinetic Power Substituting the value of Generally speaking it will be desired to have a value of a less than 0.01. Smaller values of a. are not of practical concern. Hence upon substitution of values for U and p in (44) and upon choosing a value of a equal to 0.01 the value of 1c thus obtained may be termed kmax, or the limiting maximum value of mobility, for the given velocity and power conditions for efcient conversion of kinetic to electric power.

The following empirical equation for the mobility of a charged particle is from Millikens work on charged oil droplets.

According to the kinetic theory of gases, the relation between mean free path and gas density is Substituting the value of l from (46) into (45) the following equation is obtained C11 Cl k-'(1+) (47) where CLN@ and :5873 5..'1' (48) In the following table Values of C are computed for various gases from values given in the literature:

In Equation 47 when the following condition obtains Then Equation 47 may be written:

CIC/l Also:

CIC! l 0- -daoz (51) 50 k=K0 Y (52) k and 6o are next eliminated, by substituting the value of 60 from (35) into Equation 52 and equating the resulting expression to the value of k determined by Equation 44. From this, a solution results giving the value of Ko:

d KO-Io,

Putting the following values, for air, into (53) e=0.01; b=2.50 106 and u=1.29

the following evaluation of (53) is obtained:

For example, a typical gas-now velocity of meters per second may be chosen; and putting this value into Equation 54 there is obtained a mobility of 3.11 10-7 meters per second/volt per meter. This is the order of mobility observed for the so-called Langevin ion, formed from water vapor. Other ions or charged particles in this range have been observed with hydrocarbon mist, phosphorus smoke, zinc or zinc oxide clouds, ammonium chloride clouds, mercury clouds and `cadmium oxide clouds. In general, aerosol particles usually have a mobility of this order, or, what is most desirable for reduction of frictional power loss, still lower mobility values. The values of mobility, herein calculated, may be considered the upper limit in the mobility of the particle, requisite to the achievement of low relative slip or frictional power loss.

(b) Minimum particle melius foaefficient operation To determine the minimum particle radius, au, required to achieve a mobility Ko not exceeding that value given by Equation 54; Equations 51 and 53 are equated and solved for ao, with the following result:

The order of magnitude of au may now readily be obtained by substituting values for air, as follows:

From (48) The value of viscosity chosen for the above calculation is given for air at 450 K.; and the The values of minimum particle radius, au, for ei'cient operation, 'yc=0. 9, have been computed and are given in the listing under Examples I, II, III. It will' b'e noted that ydo varies very little under the various operating conditions assumed, from dt=1.27 108 to ao=`4 10-8. Of course, the larger value may be used in all the examples given, without appreciably affecting the results.

In considering thev minimum value of particle radius, a0, that may be employed under certain conditions of operation, it will be helpful to select the largest values of U, n, and the smallest values of N and b'which are likely to be used; and then calculate the smallest value of ao from (55').

The factor C" is inversely proportional to the viscosity 1;. The viscosity 17, in general, increases with the temperature and therefore higher temperatures favor smaller values of C. Equation 52 can be modied, in View of (45), to take into account the temperature variation of viscosity:

' 30,77! Y k K 507' (57) With respect to the viscosity coefcient, physical data giving the range of variation for n shows, forv example, that water vapor at 270 K. has a viscosity of 0.8)(-5 m. k. s. units of viscosity, and at 650 K.: 2.5 105; while, for mercury vapor the viscosity at 650 K. is 2.50 105, at 510: 4.50* 1O5, and at 750 K.: 8 1Or5. The latter is the-#largest value of n that is likely, and in any case, the range of variation is about 10/1.

Equation 45, which is the basis for the derivation leadingto' Equation 55 and the numerical results therefrom, has been shown not to apply below radii of less than GX10-10 meters. Fortunately, the present analysis leads lto a particle radius well above the lowest range of applicability of Equation 45. Y,

Because of the disadvantages of using a value of; b less than that of air, let us take b=2.50 106 as kthe lowest value of b; let us take the largest value of n=8 105; and use the lowest value of C1=1'.24 108; for hydrogen. The largest value of U that can be used, in Fig. 12, with vl=0.9 is about 100` m./sec. Putting these miscellaneous limiting yphysical values into (55) we obtain a lower limit for particle radius:

least a0 102 X 10 2 1.8 10g meters (c) Optimum particle radius (d)r The' ratio off solid liquid particle densit; to gas density The mass of solid or liquid particles per unit volume of as is given by:

.16 In (57.1),- the` value for. n was obtained from (4)..and N is taken equal-.to 1.- y *I Y Substituting for i from (40) dividing through and 6c from (35),. andY simplifying there is obtained the ratio:

@stars K Fu'-a-pag Evaluating the constant. terms:

In the" following Tablef5i, thevalue.l of I isv com-- puted for the' various conditions previously set,

Thus, the aerosol solid or liquidl particle mass per unit Volume may varyy from about 0-.1. to 301% of the gas density.

Referring to Equation 5.7.2 it will be noted that l" depends only on the factors b, L, ac3, 6p and that all other variables; such: as z', E.y U. etc; are automatically accounted for when these factors are chosen. The value of' l1v must be less than 0110,. however, forfthe assumption" c='=c, upon which the derivations. herein. are made, toy be reasonably accurate. This does not meanthat devices inf which T 0'.10v will: not bek operab1e,.bu't, thatk corrections must bei-made, in such case; toi the. equs'rtions.V previously' derived', sor thatv accurate computations may be'I made with' I 0.10.

VIn'. this connection, consideration of Equation 57.2 shows that', other'thing'sl beingv constant, the magnitude of lis. mostv affected by' variations in particle radius;y that is I* variesi as ac3. But', Equation 55 shows that au varies inversely as the square root of a, the slip factor. I-Ience.

1 rag/2,

so that by increasing a from .01', which was assumed in all previous. calculations, to .04' the magnitude of 1` in all the calculations of Table 5 is reduced by a factor' of 8. Thus, when the slip is 41%,. inat'alolev 5. does not'exc'eed .0321 or 3.2%, and all the equations heretofore' derived'. apply, to a good approximation. Moreover, the efElciency of conversion of kinetic to electric power is not materially reduced.

(e) Iom'zatz'on of the aerosol particles However, according to Fundamental Processes of Electrical Discharge in Gases by Loeb, p. 149, 1939, Wiley: ions of radius below -s meters take on charges of the order of a single electron, and the rate of charging is surprisingly rapid for ions of the order of 10"l meters. Hence, in the above calculations, the chance of an average of one electron charge per particle was indicated. Even if several electron charges per particle are obtained, the order of magnitude of the numerical results will be not essentially changed.

The maximum charge per particle, according to Pauthenier, varies as the square of the particle radius; and the mass per particle varies as the radius cubed. Hence, for a given charge density, coulombs/metera, the total aerosol mass will vary directly as the particle radius. The conclusion from this is that smaller particle radii, and more particles, with one or several electron charges per particle, will result in a minimum aerosol mass required to carry a given charge density within the gas mass.

Hence, in the present invention, it is preferred to use particles of such radius (say 2v to 8X1()-8 meters) as to fulfill the latter condition, with the slip factor a. not exceeding about 0.04.

(e) Nature of the particles Various chemical smokes and clouds which may be employed in this invention have been disclosed, and the type employed depends on the design of the generator. In generators employing negatively charged particles, it may be desired to employ electron-binding materials to comprise the particles. For example, diphenyl chloride (commercially known as Aroclor) mist may be utilized as an electron-binding material. Other known materials have, in a similar way, a tendency to remain positively charged, and thus tend to lose an electron, and are thus more suitable for use as positively charged particles.

In general, materials of high dielectric constant, or metallic particles, are preferred since these have a greater charge-binding capacity in the ratio e being the dielectric constant of the material relative to free space; and 5:1 for metals.

3. THF: NozzLE AND THE NozzLE PLATE Figs. 1, 2, 3 and 7, are views of the nozzle, and the arrays of nozzles in the nozzle plates.

The nozzles are set side by side and spaced as closely as possible. The total cross-sectional area of all the nozzles, taken at their throats, may be related to the total plate area, by a packing factor fo.

The electric power density, p, of each nozzle, and the packing factor, fo may then be used to determine the average electric power density p' of the nozzle plate, thus:

It will be seen hereinafter that the initial and nal diameters of the nozzle, D1, and Dz, and the length thereof, L, is related to the fraction, ry, of the kinetic power converted to electric power.

Given, the nozzle throat power density, p; fy, and qs, the nozzle dimensions D1, Dz and L, may be computed. As may be seen from Fig. l2, p and 'y uniquely determine 18 and iL, so that given L, the voltage, E, and current density, z', at the nozzle throat, are also then determined.

The relation between y, L and D1, will now be found under the condition of no thermodynamic change on the conversion space; that is AUzconstant. Referring to Fig. 8, it will be seen that:

Let yzproportion of kinetic power converted to electric power then 1/2MU12- l/2MU22 (U2 2 M2M-w 1 (62) But, since ArUrzAzUz;

In Fig. 11, Equations 66 and 67 are shown, with -y plotted as abscissa; and, f, and L/D1, for :20, as ordinates.

Fig. 2 is a fragmentary view of the nozzle plate normal to its face 22.

It is now required to determine the packing factor, fo, for the ratio of the throat area of all the nozzles to the total area, allowing enough wall thickness between the largest sections for purposes of strength:

segments of four circles, totalling the area of one circle of diameter D2.

accepte Hence, with y=0.9, the relation between the power density, takenat the' throat of the nozzle, and the average power density over the entire nozzle plate is given approximately by ptr-0.25811 4. VOLTAGE-CURRENT'CHARACTERISTICS.

Eliminating U, between Equatibns'- 39" and' 40, the following is obtained:

Evaluating the constant terms L='1 '10'-3 meters (1 mm.) #campa/mettere 7:0.9 FOR AIR by (75) High Dielectric Gatsby (76)' E voLTs 13,080- 6-10'0 In Fig. 1 there is shownzoneform'. of my invention for converting the heatenergy contained-ina gals.: or vapor, at relatively high pressure, andV temperature, to electrical energyvl 'I-ofobtainf con-i trolled expansion and consequent satisfactory conversion of the gaseous heat energy in a chamber 2 to controlled directed kinetic power, and subsequent conversion thereof into electrical power by the slowing of the charged particles in the nozzle under the iniiuence of the counter-l rleld` in the nozzle, the latter must be of gradually tapered form. Owing to the requirement for a veryshort nozzle length,L, and because the nozzle-must be of'gradually tapered form having a- 'considerable change inl cross-sectional area,l

the nozzle will have a very small cross-'sectional area. However, in order to obtain the production of power on a largeJ scale. it is necessary to have a lar-ge nozzle. area. These conflicting requirements I have resolved by the provision of a plurality of nozzles Ha, Ilb, i Ic, etc. arranged side by side in the compcsite plate 5, 1, 9. This enables a suiciently large total area of nozzle cross-section to be provided, thus enabling any power output to be attained'.

The gas or vapor, containing aerosol particles, la, is admitted to chamber 2, at relatively high pressure and temperature; The chamber',", cdmprises two facing parallel walls 3 andi, compris-1 z5 occurs in long nozzles and tends to limit current 20?' ing` layers ofinsulatingl materialy 5 and Bysuch as ceramic, over 'conducting sheets 1- and 8- respec tively; The conducting sheets 1f and..V 8, may comprise a mtal; such as' copper, between ceramic plates 5'and9', 'and and t0, respectively. Within the composite plates 5,- 1=, 9- and 6, 8,. |10 are formed a plurality ofadjacent nozzles Illa, Hb,y Hc .,etc.,E in plate 5, 'l-, 9;y and I'2a, |2b, l 2c in. composite plate 6, 8,. Illa.` The nozzles IIa, lib,y

Hc, are'terminated; inthe conducting` rectangular box lHt,4 and the-nozzles' |20, 12b, |20 are ter-- minated in the conducti-ng rectangular box M. The purpose of the. conducting boxes' terminating' the nozzles, isY to' discharge the aerosol par--y ticles or ionsin the: gas` stream; at the nozzle exit. The centers of the boxes, t3' and. lf, can also be provided-with wire felt pads; such as l5 andt6, between supporting meshes t1, I8 and t9, 20' respectively. These pads function to dissipate the excess velocity of the vapor issuing from the opposed nozzles, and also assist in discharging the charged aerosol particles. The boxes t3' and t4 constitute an enclosureand the charged particles issuing; from the nozzles tend' to tra-vell to the' walls and discharge thereon'.K The electric eld is set up betweenr the-wall 20 of thebo-x. I3 and the sheet 'I and this constitutes the counterfeld against whichl thenega'tively charged particles in nozzles Ha, H b3.. must move, Centerlines AA andf'BBf dene a-section. Additionalsections can= be'arrangedu parallel stacks. InFig.

1., for example, 2t and 2'5 comprise the ends of twov additional sections?.V lI-`he nozzlesy themselvesare constructed` to' obtain the desired reduction inv'elocity from inlet; to exhaust', and. are made with a' taper of say 20"., sof as to givecontrolled expansion. f

The electricalA length L: of they nozzle isthc distance between sheet 1 and the face 20 and thedistance. betwen sheet ily and the face 22. The length L,.. according to my studies, should be as` short as practically possible, preferably less than 10;-2' meter; orl better stillI say 3x10*3 meters. The smalll value for L' is requiredto. reduce the effects of space charge. Excessive space charge ow, and to build up` ar high voltage. By the construction shown in Figs. 1 and 2, it is possible. toi obtain a relatively high. current per unit l area; and a1 relatively lowV voltage'. These factors have been rather fully discussed in the preceding mathematical sections;

Within they chamberA 2k are disposed parallel spaced conducting'. grids 21 and4 28. Connected to' the-grids Hf and 28' isla high-frequency voltage source 29'. The'- voltage) between 21 and 28 set suinciently high to cause extensive ionization of the gasfin the space 3c between gri-ds 2? and 28, thereby producing ions, 3l, 32 of positive and negative srgrr. The distancebetween 21' and 28'sho'uldf be small,.so`I that a relatively low voltagev can sulice toionize the gas- Il,- and so that' the ions can be formed within such a narrow sheet that they can be quickly drawn apart by the steady electric eld applied between electrodes l and 8, before they can recombine'. Thus, a positive potential is applied to'plate electrode 1, and

a negative potential is applied to plate electrode' 8; and accordingly, the positive ions' formed in space 3 0 are drawnt'oward the negative electrode 8, and the negativefion's formed at the sametime in spacey 3'0 are drawn to the positive lplate 1. These ions, initially positivelyv charged atoms or molecules, and free electrons and negatively charged atoms and molecules in space 30, quickly become attached to the aerosol particles Ia, suspended in the gas, I. Thus at the entrance to nozzles IIa, IIb, IIc, the vapor comprises a suspension of negatively charged aerosol particles; and at the entrance to nozzles |2a, I2b, etc., the vapor comprises a suspension of positively charged aerosol particles.

The provision of charged aerosol particles, which may comprise liquid or solid particles, is then an important feature of this invention. My studies have shown that, in order eciently to convert the kinetic energy of the vapor to electrical energy by doing work on the charged particles within the vapor in an electric countereld, it is necessary to provide charged particles of sufficiently large mean diameter that they are carried along by the gas stream without much slip Small particles such as molecules, or electrons, can slip through the gas more readily, and thus make for a viscous loss of power, and also prevent the gas from effectively pushing the ions against the countereld.

The positively charged aerosol particles, 33, are separated from space 39 by the steady field applied between plates 1 and 8. The positivelycharged aerosol particles 33 become a part of the stream of gas, or vapor, entering the nozzles |2a, |2b, |2c, etc., whereupon as the gas expands the temperature and heat content drops, and the velocity and kinetic energy is increased. The charged aerosol particles, 33, enter the box I4, and are discharged on the walls 22, 23 or on the central pad I6, causing the entire box I4 to take on a positive charge. When the device has reached a steady state, a countereld is set up by the positively charged box I4 between its side plate 22 and the electrode sheet 8. This causes a repulsion of the positively charged particles following in the gas stream in the nozzle. The positively charged aerosol particles are borne and entrained by the gas and are of very low mobility. It therefore follows that the gas must do work in shoving the particles against the counteriield; hence the kinetic power is converted to a time rate of increase of electrical potential energy, which appears at the load terminals 35 as electric power.

Simultaneously, the same type of action is occurring in the nozzles IIa, IIb, etc., with the negatively charged aerosol particles 34, and a negative counteri'leld is built up to oppose the downstream motion of the negative aerosol particles and to thereby convert the kinetic power of the gas stream in IIa, IIb, etc., to electric power at the load 35. The positive and negative charges at the box I4 and I3, respectively are neutralized, after building up to a desired level, by a flow of electrons, from I3 through the load terminals 35, to I4. A small part of the electric power generated between I3 and I4, across the load 35, can be tapped off, at 36, and used to supply the ionizing grids 21 and 26, and the separation electrodes 1 and 8. For example, ii' 25,000 volts are generated between I3 and I4, and across 35; then 2500 volts D. C. can be placed across 1 and 8, and 1000 volts at a high frequency, across 21 and 28.

The auxiliaries comprise an electrically isolated rectiiier 38 and a high-frequency source 29. A portion of the power output is supplied through a reversing switch, generally indicated as 31. The reversing switch 31 periodically reverses the auxiliary input 36. This provides a square wave 39 applied across the transformer primary 40. 'Iransformer secondary 4| supplies the rectier 38, and the transformer secondary 42 supplies small A. C. motor 43 which operates the reversing switch 31. Transformer secondary 42 also supplies the high-frequency source 29.

The reversing switch can be constructed as shown. The reversing switch device comprises a small A. C. motor, having an extended shaft 44, upon which is mounted ywheel 45, slip rings 46 and 41, and split rings 52 and 53. Auxiliary power, from the main power line output at terminals 35, is fed into the slip rings 46 and 41 via brushes, 50 and 5|, respectively attached to feeder line 36. Split ring 52 connects to slip ring 46, and split ring 53 connects to slip ring 41. Brushes 54 and 55 take 01T the square wave input 39 to the transformer primary 40.

In starting the generator, an outside A. C. power source 53, can be employed to feed power, through closed switch 51, to the line 56. This activates the transformer coil 42, which now acts momentarily as a primary, to activate the rectifier 38, through secondary coil 4I. Also, motor 43 is caused to turn, and high-frequency source 29 is activated. The voltage across I3 and I4 is quickly established, and the switch 51 then opened. This system is now entirely self-operating.

Fig. 2 is a fragmentary View of the nozzle plate normal to the face 22, with particular regard to the throat area of the nozzle I2, compared to the total area deiined by rectangle ABCD, as hereinbefore described.

In Fig. 3, there is shown, in perspective cutaway, the elements shown in Figs. 1 and 2. Aerosol 60 is shown entering the inverted funnel 62 through inlet pipe 6|. Aerosol 60 is distributed as shown by the arrows 63, 63', 63, to chambers or spaces 64, 65, 66 and 61, which correspond to the chamber or space 2 between faces 3 and 4 of the nozzle plates shown in Fig. l. The arrows 68, 69, 19, 1I indicate the now of the aerosol 6U into the entry spaces 64, 95, 66 and 61, respectively. Within each of the entry spaces is positioned a pair of ionizer grids which may consist of suitably supported pairs of wire mesh, such as 12, I3 in entry space 64; 14, 15 in entry space 65, and 16, I1 in entry space 66. Corresponding meshes are connected by common leads 88, 8| to the ionizer terminals 82, 83, which pass through the enclosure 59, and through the insulating bushings B4 and 85. The lead 80 connects to meshes 15, 11, etc. through the lugs 81, 88, etc., respectively. In a similar manner, the lead 8| connects through the lugs 90, 9|, etc., to the meshes 14, '16, etc.

The composite nozzle plate 95, 93, 91, 98 is shown broken away. Conducting layer 96 is sandwiched between insulating layers and 91. Layer 96 may be copper or graphite, and layers 95 and 91 may be ceramic. Conducting faces 98 and |69 may also comprise copper or graphite, and are bent, or otherwise formed into a U at |05, so as to prevent the aerosol from entering there. The direction of ow in the nozzles IUI, |82, etc. is indicated by arrows shown therein. The nozzles |0I, |82, pass through the layers 95, 96, 91 and 98, which also form the confining walls of these nozzles, in side by side array. The faces 98, |06, and closed top |05 form a conducting enclosure, or thin rectangular box into which the nozzles |01, |62, etc. discharge. This enclosure has a central wire felt pad 99, upon which the excess aerosol velocity can be dissipated.

The aerosol issuing from the nozzles IOI, |02, etc. at lower pressure than at the entry spaces aassgass 23k then.4 flows. as. indicated.` by `arrows. |03. out? of the enclosure, toward the: exit'. pipe ||'5` as further indicated by the arrow |04.

Inl asimilar manner, conductingA layer |05, is sandwiched between insulating layers and |01; Conducting layers |00 and I'Hrform a U enclosure having av closed top H3 and an open bottom', through which the lspent aeros l' issues as'shownby arrow H3.

Composite nozzle plate:.|05, |00, |01 containing nozzles |00,A H0, etc., and' composite nozzle plate H4, H5, 6 containing nozzles (not shown) contain. oppositely directed nozzle streams all emptying into the enclosure I3, |06, these streams all impinging their excess velocity upon the felt wire pad |'|2 located within this enclosure and giving upy their charges, a-ll of the same sign, say negative, to the Walls of the enclosure HI, H3; |08.

In: like manner, the aerosol streams entering at 59 and 10, flow in opposed directions through composite nozzle plates Hl',Y H8, H5 and |20, |-2|\, |22 and empty into enclosure |23', |24, |25, and exit toward pipe H5 as shown by arrow |25. The central wire felt pad in enclosure |23, |24, has been omitted for clarity of illustration.

Alternate enclosures are charged positively and negatively, Thus, if enclosure IH, H3, |03 receives and discharges the negatively charged streams, then, the enclosure |23, |24, |25 receives and discharges the positively charged streams. f

Bus |25 extends through the insulated bushing |28 and through the casing 59 connecting with lug |30 attached to positively charged enclosure S8, |05, |00, and with lug |32 on the next positively charged enclosure |20, |24, |25. Thus, all the positively charged enclosures are electrically connected to the bus |25 which is brought out through the casing 59.

Bus |21 is connected to the lug |3| attached to the negatively charged enclosure HI, H3, |08, and to thel next adjacent negatively charged enclosure |33, |34, |35 by lug |35. Thus, all negatively charged enclosures are electrically connected. to bus |21 and brought through the casing 59 through the insulated bushing |29.

The inner walls of the casing 55 can be formed of insulating material |31, such as slate, and all the plateelements can be located on suitable insulating supporting members such as angle iron |35, and ceramic insulator |38.

The separation electrodes comprising conducting sheets S5, H5, |2|, etc., are all connected electrically by lugs |42, |43, to lead wire IM; and the separation electrodes |00, ||8, |41 are all connected electrically to the lead wir@ |40. Lead wires |40 and |4|, and the separation electrodesto which they are connected are maintained at a suincient steady potential difference, by an auxiliary supply source tapped from, but

electrically isolated from, the main power output,

to eiect the separation of the ions produced by the ionizer grids, as explained in connection with Fig. 1. In Fig. 3, lead |40 is maintained positive, and lead |4| is maintained negative.

By the construction of Fig. 3 there is provided a plurality of nozzle plates. In this manner,

there is obtained a short nozzle path length, with any large cross-sectional area of nozzle required. Minimum practical voltage output, and large amperage, to any extent required is thus assured.

A single pair of ionizer grids serves to ionize and charge the aerosolparticles and to charge the aerosol in opposing directions through la pair Z4 of adjacentv nozzle plates, thus utilizing both the negative and the positive ions created between` the ionizer grids.

lPairs of nozzle plates then discharge, in opposing directions, charged particles of the samey sign into the same enclosure.

rIhis pattern is repeated, and like elements are electrically held together. Auxiliary apparatus such as shown in Fig. 1V can be employed in connection with Fig. 3.

Fig. 4 is a modication of my invention, in which ions of one sign, and charged particles of one sign 'areproduced These-may be either positive or negative, depending on the conditionsl of operation'. For the sake of simplicity only one nozzle is shown, although it will be understood that the nozzle array and certain other features of construction in Figs. 1, 2 and 3 may be employed.

A suitable aerosol is supplied through inlet pipe |5| to the chamber |52 which comprisesv a rectangular conduction box having conducting walls |53'and |54. The nozzle plate comprises insulating plates |55, |56, sandwiching conduct,- ing plates |51. Mounted within the nozzle, which is generally indicated by |58, is a plurality of points |59 which Iare shown radiating from contact |60.

Fig. 5 is a section on the line C-C in Fig. 4. The pointed conductors |59 can be mounted on the conducting member |60 which is supported by the conducting structure |0|, |62 and |63, attached to, or forming an extension of the con-v ducting sheet |51. The nozzle |58 empties into chamber |64' which also comprises a rectangular conducting box having facing walls |65 and |66'. The center of the chamber can also be provided with a Wire felt pad |61. The electric circuit employed for actuating this device comprises a reversing switch |10 similar to that shown in Fig. 1. The reversing switch 10 functions to reverse the direct current taken off from leads |'1| 'and 12, and toy produce therefrom a square wave |13 which is applied to transformer primary |14.

@The transformer |15 comprises a step-down transformer which may for example have a stepdown ratio of about 100' to one; and which functions to reduce the potential and to increase the amperage output of the generating system. The output is taken off the secondary winding |16 and transmitted to the load via the terminalsy |11. A small portion of the output is tapped from the secondary |16 and utilized to operate the small reversing switch motor |18. Another secondary coil |19 is utilized to tap off a further small proportion of the output power and to rectify back to direct current by means of the conventional rectifier components |80, 8| |82 and |83. The rectified voltage is applied across |12 and |84 and utilized to operate the point ionizers |59. A startingv battery is employed to initiate the ionization in first starting the device, and is subsequently disconnected.

The operation of the device shown in Figs. 4 and 5 is as follows: Aerosol particles |50 are admitted to chamber |52 and a positive potential is applied to the wall |54 of the chamber 52 relative to the points |59. A potential difference of about 3000I volts may be maintained. Each point |59 will emit about 1 to 2 microamperes in air; or about 50 microamperes if the atmosphere employed is pure nitrogen. If 40,000 nozzles are employed per square meter (one of each 5 mms. x 5 mms. of nozzle-plate area) and 10 amperes per square meter output, with nitrogen as the:

gas, is to be obtained, than points will suffice for ionization in each nozzle. Other conditions of operation will, of course, alter these calculations. Electrons, emitted from the ionizer points of |59 are shown by the minus signs |85. These electrons become attached to the aerosol particles |50 and cause these particles to be negatively charged. Thereafter, the operation is similar to that previously described. The box |64 becomes negatively charged relative to the conducting sheet |51, and the circuit is completed by the now of electrons from |64 through lead |1| through the reversing switch through the transformer primary |14 and back to the conducting sheet |51, thence to the ionizer points |59 and out from the points into the gas stream again as free electrons |85. Aerosol particles |50 are negatively charged in passage through the nozzle in the vicinity of the ionizer points. The negatively charged aerosol particles are indicated as |86. The spent and discharged aerosol particles |81 flow through the exit pipe |88. It will be understood that the inlet pressure and temperature at |5| is higher than the pressure at |88.

When the device, in Fig. 4, is operated with a negatively charged aeroso1, electrons |85 emitted from points |59 may remain free, or become negative ions by attachment to gas atoms or molecules depending on the nature of the gas. In either case, the mobility of the free electrons or negative ions will be relatively high, and the gas stream will be unable to drive the electrons or negative ions down stream against the repelling electric field maintained in the conversion space between sheets |51 and |65. The electrons or negative ions tend rather to move toward the plate |54, which is positively charged relative to the points |59Y and are thus subjected to bom bardment by the large number of uncharged aerosol particles |50, which thereupon pick up the free electrons or negative ions and become Charged. The Charged aerosol particles, however, have extremely low mobility and therefore are entrained by the gas, and are constrained to move forward into the conversion space of the nozzle, in which a repelling electric eld is maintained between conducting sheets |51 and |65. In the conversion space, the charged aerosol is slowed down by the repelling electric eld and the kinetic power is converted to electric power as previously described.

In Fig. 6, there is shown a fragmentary view of another embodiment of this invention. The construction shown in Fig. 6 is similar to that of Fig. l except for the ionizer grids, which comprise porous ceramic plates |90 and |9| having conducting meshes |92 and |93 on their inner faces. The porous grid structure serves to conne the readily ionizable gas Which is shown entering the space between the porous grid-plates as arrow |94. The readily ionizable gas employed may comprise hydrogen, nitrogen, or other suitable gas. This gas is supplied rbetween the porous grid structure at a somewhat higher pressure than that of the gas in the spaces between the outer faces |95 and |96- of the porous grid structure, and the faces |91 and |98 of the nozzle plate array, A highly ionized layer of positive and negative charges are produced between the ionizer meshes |92 and |93. The meshes |92 and |93 may be activated from high frequency source 202.

In the spaces between faces |95 and |91 and |96 and |98, there is introduced an aeroso1-containing-gas of high dielectric strength indicated by the arrows |99 and 200. Such a gas for example may comprise diphenyl chloride containing liquid droplets or solid particles of high molecular weight diphenyl chloride. In certain cases, it may be desirable to employ chemically different aerosols for the negative ions and the positive ions. Thus, for example |99 might comprise a low molecular weight diphenyl chloride gas containing a suspension of high molecular weight polymeric diphenyl chloride for the aerosol particles. The purpose, in the case of aerosol |99, is to provide an aerosol particle having a high binding or attractive force for the electrons or negative ions introduced into the spaces between and |91 under the attraction of the positively charged plate 20|. The electrons or negative ions are caused to traverse the porous structure |90, being drawn out of, or from, the highly ionized layer of gas |94.

In similar manner positive ions may be drawn out of the ionized sheet between the meshes |92 and |93 and caused to traverse the porous structure |9| under the attraction of the negatively charged conducting plate structure 203.

The gas pressure of the readily-ionizable-gas |94 between the porous grid structure is maintained at a higher pressure than the gas pressure of the gas on the outside of the porous grid structure, thus causing gaseous diiusion from the inner to the outer faces of the porous grid structures, thereby aiding the migration of the positive and negative ions outwardly through the porous grids. The gas in the space between the faces |9| and |98, indicated by the arrow 200, may comprise an aeroso1 metal vapor, such as mercury vapor containing suspended therein condensed droplets of mercury.

Fig. 6 shows two aerosol working substances in two closed circuits-one for the gas-polymeric aerosol working substance, such as diphenyl chloride vapor, and a second chemically different aeroso1 working substance such as mercury vapor. Gaseous diffusion aids the positive and negative ions of the readily-ionizable-gas, such as, nitrogen or hydrogen, to diffuse, aided by their respective attracting fields into both of the aforementioned aerosols. The readily-ionizable gas may later be separated from the aerosol vapors and can be drawn off by pumping so as to produce a contlnuous circulatory cycle for the two diierent working substances.

The two thermodynamic cycles with the two working substances are indicated by the dotted closed curves 204 and 205. Arrows 206 and 201 indicate the small amounts of readily-ionizablegas which may be exhausted from the system or returned continuously after purication to |94. An electrical system similar to that shown in Fig. 1 can be employed in connection with Fig. 6.

Fig. '1 is another form of my invention, adapted to operate directly from combusting gases, which is constructed as follows:

Nozzle plate 2 |0 comprises an array of nozzles 2| la, 2|Ib, etc., formed side by side in a heat resistant ceramic insulating plate. A series of nozzle plates such as 2|0, 2|2, 2|3 are arranged in parallel stacks and fed with an oxygen rich gas such as air generally indicated by arrows 2| 4 and 2|5. The gas is fed between faces 2|8 and 2|1, and faces 2|8 and 2|9. Face 2|6 and face 2|9 areA formed from metal sheets which can be deposited electrolytically on the face of the ceramic nozzle plate 2|0, and the ceramic nozzle plate 2|2. Plates 2|1 and 2|8 may be made of either insulating or metallic materials.

i 27 Hollow fingers 220, 22|. e tc'.; are screwed or votherwise fastenedto. `holes in theplate 24,1r In a similar mannerhollow neers 222..a11f1 22.3 are fastened. into `holes in nthepla-te 2 l 8 Between plates. 2 I 1 and .2 l Ill are two conducting plates 225 and 226 separatedmby an insnlating plate `22-'L ,Into theoonducting plate 225 there .is screwed o r otherwise fastened c or 1 1;l uc ting v probes I221i and .229.. At the .end othe conducting probe a. plurality. .Qf points 23g-and 2,3 I are mounted on i228;alnd, 22.9J .lepectiyelyg In the saine Way probes ,232 .andza are. iastenedV t0 plate 226- Rmbes. 2322.11@ 2- 33 eaeh 11a-Mea plurality .Qt-t0n.- -ducting jpoints, 23l an d 235.l `'Ihe c ondnc-tlng probes arfeplaced Within the hollow fingers 22D, .z2 n. ..222 .and 223.. ...The .Cond-mme, pdmts are iocatedwithinthehollow nnsersibeneath a Series nf. nolesor generations. 2 3@ and 2:31` Qnllollow linger 220, and 2.38,1 123.9 .@Ilhollw gr1er-f22 .Holes Maanden areloaied on insel' zzaandjzand. 24.3 911 hollow-flog.. L23... .The hollowngers formed .from a resistant. ill.- .suiatinefcera-mic material and tipsof theneers are formed into stream-line points 2M,- .2.45, 24e-anew. ...Combustible eas Srlch as hydroserltfleihane, .sthanepneasoline-weer.. sie.. ateshownriterieg :the space hgetweenihs 1 @S211 @iid ZerfQW .24.8. and the same or .miler type leises is .Shown .euteringiihe.spaahetween wand 2.1.8.2@ the arrow 2.4.8, .The wmbutble eases f.24.;. the .hollen risel's 2.20..-311'1 Z2 l .andere forced. Dui. ef

2.536%.. 31....0n .D .and 238.. 23.9.,011 3!- .Ia similar meenernmbustihle eases Zweiter .me hollow nnee..rS -.2 ?2.er,1d aami.. are! ...Ced @1.1i or. Q ries 2.40. 2.4.! and 242.', .2143 resfrzetvely- The nozzles 2l le .1214.112 empty.. interi@ tendini.- inesh9a-25t-pand th .charged Hotel .entitles l' Well .-25.1t ...Ther/162.2165

pla

are shown`operati'rig `posit i o Vthe walls y. l etc., ofsthe c The nais* .The sen'sfqmr @bres instaan tta. Leads-rwandaise fejdp wer' `261 and.. 25B respectivelm'and vJlQvide isolated TD.' 'CSO "limits from' the transformer sec 'on'daries fthe-@s ftrf-t'fcssiuerameatteints s einen S and. 253 "thus, iaksdna .negative charge nga; eine No., .respectively @atouts imm tr'on's canI beachieved; and strong electron currents can be sustained'.

In operation, then, the Aconversion of the kinetic power of the ga's in the nozzles r2| laf, and 2Mb, through the intermediation of the positively Acl'rarged particles, :and the repelling `eld between layerst25l and 216, is `generally simi-lar `to the process described in connection with Fig.. 1. In 'the v'same marmer.,` the conversion of the kinetic power of .the `moving gases to electric power in nozzles 25211 and l252b; through the intermediationfof negatively 'charged particles 212,-is aga-in generaliysimilar to that described in Fig. 1.

The modification 'shown in Fig. 1 is distin- :gnished .from the preceding ig-u-res in that the 'combnstiblegases 268 issuing from orifices lsuch vTas 23%. and 231 combine withy the oxygen rich gas v211|` yand produce by an exothermic ehem-ical combination, vor `the process known as combustion, "an increase in temperature and heat vcontent, in the region within the nozzlegenerally indicated by the brackets 213, and 214. Subsequently in the Vregion, vof the throat of the nozzle generally Aindicated by the brackets 215, and 216., the-heat energy previously given tothe igaslby the process of combustion, is employed to 'increase the kinetic power oi' the aerosol by the v'eimansion -Of fthe gas between the reg-ions 213 and "215, and 214 and 276. Thereafter, the conversion from-kinetic'power to electrical power isgenerally .similar to theprocess previously de- #scribed connection with the preceding figur-es. The `aerosol :particles Within the-gas 2M and v215 are originally nncharged, and are indicated as '2J-'L l'and :218. These aerosol .particles comprise heal-,resistant materials, i. e., aerosol particles such as silicondioxide, or metal oxides, such fas iron oxide,v whichrnay be 'produced in known mannen VFor example, colloidal'liquids, contain- 'ing these-particles in suspension can be intro- ;ducedjinto thegasstreams 2| 4 and 2I5 priorto theentrance'of `said gas streams into ythe device "ofEig?.

The j-operation ofthe ionization and charging -ofthe aerosol-particles maybe `understood b'yfreference tonozzle 2 52a and moreparticularly'to the points2 34,j at 'theendof the probe232. electric held- 218; is applied by means ofv the rectil'fier 261Which lis connected to the plate2 I9 at its positive terminalfand tothel plate226 at its negative terminal. A probe 232 -conductsthe ,-potentialf'lom thegplate 122-6 to the points 234. The nnigfer 222, lloci-ng an Ainsulating material and containing the -orces'240 4and 24I ,'permits the electric'eeld'to traverseconcentrate and terminate at'the point'2'34. ."The'points234, beingrlocated .inwthe .readily-ionzable-gas 249, emit free-electrons. The free electrons are directed by'theeld 2J8"toward"the plate 2I`9. #These free electrons taretshwn as :minus signs,- generally .indica-ted' as 219. q'lilneifreeelectrons a-re thus vdravsn out 'into the region of the vflowing 4aerosol. in lwhich there Tazze .present 'molecules- :having electronic an'ity, such .as oxygen` and water. I'heseproduce' nega- 'ativef'lionscf intermediate mobility. Uncharged aerosolfparticles also rflow :into the nozzle-*25M 'andfare'lcased to collide with vthe concentration lof '-freeelectrons andI negative ions 219 at 'the en- '.t-r'an'cefof thenoz'zle. The' uncharged aerosol particles 21z8-puiok vup these negative 'charges and "'be'come' Vnegatii'rely charged-aerosol particles 212. 'Ifherealften conversion of kinetic powerA to elecftrlc power *proceeds as' prevosly described.

f-Pheaction'of theitiye'ions in nozzles2l la,

lightly-inlener ibnfzer'ylt- 

